Hill and McGraw, both 49, recently celebrated a huge milestone in their relationship on Oct. 6, when they officially marked off 20 years of marriage. McGraw Instagrammed the sweet note Hill left him on the day of their anniversary, when she wrote "20 years" in a heart drawn in lipstick.

The couple actually met and fell in love on McGraw's Spontaneous Combustion tour, and McGraw told the sweet story when the two were honored with their own stars on the Music City Walk of Fame in Nashville, Tennessee, earlier this month.

"I had a really hot chick on the road with me," he joked. "And I fought, and I fought, and I fought to stay away from her as long as I could, and that lasted about as long as her job at McDonald's. I'm not gonna go into detail, but it was a great tour. I can tell you that."